1. Insulators and Conductors

2. Review From Last Class…
What colors and materials best absorb radiant heat?
What colors and materials best reflect radiant heat?
What is it called when the radiant heat goes directly through the object instead of being absorbed or reflected?
What is the largest source of energy on Earth?
How does the Earth stay warm?
How do plants use the sun’s energy?
What technology powers your calculators (specific name)?

3. Radiant Heat Demo
You will have 15 minutes to wrap up the graphing and conclusion questions for the Radiant Heat Demo from yesterday’s class
If it is not completed in this time it will be homework.
Notes on radiant heat will be passed out as well

4. Conductors and Insulators
Conductor: any material that allows heat to be transferred easily
Insulator: any material that is not a good conductor of heat

5. Why Insulate?
Insulators can be used to prevent heat transfer between objects- to keep hot things hot, or cold things cold
For example: in the winter you wear coats and warm clothing to keep your body heat in; your house contains insulation in the walls and roof to keep heat in

6. Insulators Thermal insulators work by trapping air around and object
If the object is hot, the thermal insulation prevents the heat from escaping the object, keeping it warm
If the object is cold, it prevents the outside heat from mixing with the object keeping it cool

7. What makes a good insulator?
Less dense materials are better insulators (atoms are more spread out- harder to pass energy)
Objects that reflect radiant heat are also good at insulating (reflect heat away keeping insulated material cold, or reflect heat back onto warm objects)

8. How do I know it’s a good insulator?
Thermal Conductivity: The rate at which a material conducts heat; objects with low thermal conductivity are best at insulating
R-Value: The R-value of a material is its resistance to heat flow and is an indication of its ability to insulate. It is used as a standard way of telling how good a material will insulate. The higher the R-value, the better the insulation.

9. Thermos Project Solo or in pairs
Must create a “thermos” to keep 250mL of hot water warm
Research properties of materials, design and construct a thermos as well as an Advertising Pamphlet for your product

10. Thermos Requirements Must be able to hold 250mL of water
Must NOT contain any heating device
Must NOT contain any part of a commercial Thermos flask
must be easily portable
must have a lid that is able to open (to pour liquid in)
Must contain the plastic tube provided in order to insert a thermometer for testing.

11. Pamphlet Requirements
One 8.5x11 size piece of paper
Must follow the format below:
Name of Thermos
Picture of Thermos
Slogan for Product
Labelled cross-sectional diagram of the inside
Description of materials used and other features
Product Warranty
Name of Company
Contact Info

12. Other Details Due date is Wednesday May 11th
Presentation will be “Dragon’s Den” style; we will have guest evaluators that will come in and assess your thermos/design/marketing technique
2-3 classes will be provided to do research/work on pamphlet; construction and materials will not be provided